Vacuum still



J. H. HILLS VACUUM STILL Dec. 6,1932.

Filed Sept. 20'. 1929 s Shets-Sheet 3 ME 475. Jofin lznr 171116 @,e

Patented Dec. 6,,1932

UNITED s'rA'rEs .-1,89o,1sz

PATENT OF C mm 1:. arms, or GRAND wins, n romean, ASSIGHOB 'ro nousm no. 00., A oonrona'rron or women:

vacuum: s'rrnr.

Application fled September 20, 1989. Serial Io. $83,888.

normal operating v'acuumin the still is utilized to draw in fresh charges of the liquid as required by variations in the liquid level in the vaporizin chamber and the fresh charge is passed t rough a preheater or heat exchanger installed in the vapor discharge line from said chamber in order to utilize a portion of the latent and sensible heat of the vapor before it is condensed.

It is another object of this invention to' provide an improved heating system for the vaporiz ng chamber comprising a steam calandria for supplying dry heat to the liq: uid in said chamber, together with a steam siphon jet actin both to 'increasethe vapor pressure of an to agitate the contents of said chamber." i

It is also an important object of this invention to provide an evacuating jet for starting up the still quickly by expelling the air from the chamber and displacing it with steam which is rapidly condensed in the condenser creating a vacuum in much less time than would be required were the vacuum pump depended upon to'do the whole work of exhausting the air from the still-and condenser.

, It is a further object of this invention to provide an improved feed regulator incorporating a bypass adapted to permit manual regulation of the fluid level in the vaporizin chamberwhen desired. 4 l

t is still another object of this invention to provide an improved condenser and preheater mounting and arrangement that will Hermit changing the position of the con nser relative to the still to suit various installations without requiring alteration of the vapor discharge line from said chamber to the preheater and condenser.

Other and further important objects of invention will be apparent from the dis- 'throu h closures in the specification and the accompanying drawings.

This invention (in a preferred form) is illustrated in the drawings; and hereinafter more fully described.

On the drawings:

Figure 1 is an elevation of a vacuum still system embodying the features of this invention.

Figure 2 is a central vertical section thereof. a

Figure 3 is an enlarged detail section of the feed regulator.

Fi re 4 is an enlarged detail section through the vapor dischargeline with the preheater in elevation.

Figure 5 is an enlarged horizontal section calan ria.

Figure 6 is a fragmentary vertical section on the line VI-VI of Figure shgwing the inlet pipe from the preheater in elevation.

Figure 7 is a fragmentary plan view of the still showing the adjustable mounting of the condenser relative thereto. As shown on the drawings: a The vaporizer chamber proper com rises a cylindrical vessel formed of top an bottom sections 10 and 11, the abutting edges of the sections being flanged as at 12 and bolted together. The joint so formed also receives the upper tube sheet13 of a calandria, the

lower tube sheet 14 thereof being welded or otherwise secured near the bottom of the lower shell section 11. These two tube sheetsthe vaporizer chamber above the are connected by a number of tubes 15 com: Y

municating therethrough and containing spiral deflecting strips 16 which assure a more intimate contact of-the liquid with the tube walls. Within the calandria a large central tube 17 is provided which permits a central 'downward flow of liquid balancin the upward flow through the tubes 15 so t at a con stant circulation of liquid is thus obtained. The space within the calandria surrounding the tubes and between the tube sheets forms an annular steam drum submerged or partly submerged in the liquid to be=distil1ed.

This steam drum or calandria is supplied with'steam through a valved inlet 18 from 5 a changein the direction of the feed piping a steam supply line 19, branches 20 and 21 from this llne serving evacuating jets 22 in the up er part of the still, and an agitating jet 23 elow the calandria, which latter jet is in the form of an ejector or siphon Jet drawing liquid through a pipe 24 from the bottom of the vaporizer and discharging the steam and liquid into the body of the liquid in the vaporizer beneath the calandria to agitate as well as heat the liquid, a small admission of steam at the jet having a high heating value upon starting up because of the latent heat released by the condensation of the steam. The evacuating jet 22 is provided to assist in establishing the initial vacuum when starting up, as by introducing steam at this point until the air has been driven out of vaporizer and the subsequent condensation of the steam rapidly creates approximately the required operating vac-' uum.

A raw liquid supply line 25 leads to an inlet connection 26 on a feed regulator body 27 containing a float 28 operating in a chamber 29 which is connected with the vaporizing chamber above and below the liquid level therein by equalizing pipes 30 and'31. The

inlet connection 26 leads to a valve 33 which.

is lifted to its seat by the upward movement of the float in the chamber 29. An outlet connection 34 takes raw liquid from below the valve 32 of the feeder and delivers it to preheating coils 35 located in a vapor conductor casing or come over 36 mounted above the central vapor outlet 37 from the vaporizer. Valved bypass 38 is also provided connecting the feed regulator inlet and outlet connections 26 and 34, in order that the feed regulator may be supplemented if desired, by a manually controlled feed. The preheater c'oils' 35 have an outletpipe 39 extending down through the vapor outlet 37 from the vaporizer to a position below the liquid level in the central calandria tube 17.

The vapor conductor casing 36 is formed as a directbridge and connectionbetween the vaporizer outlet 37 and an inlet connec tion 40 to a condenser shell. 41 which is supported by lugs 42 from the flange 12 of the vaporizer. With this arrangement the condenser can be mounted in any position relative to the frontof the vaporizer, as required by the space available for the device, and a change in the position thereof involves only 34, something well within the ability-of an average mechanic. The condenser casing contains top and bottom tube sheets 43 connected by tubes 44 through which the vapor is drawn, these tubes having spiral strips 45 therein resembling the strips 16. The casing, has suitable working water inlet and outlet connections, one of which is indicated at the bottom of the condenser in Figure 1.

A vacuum pump 46 is connected by a pipe 47 to the bottom of the condenser below the lower tube sheet to draw ofl condensate aswell as air and water, if present. Said pump discharges throu h a pipe 48 into a moisture separating an filtering tank 49. The pipe 48 is prov ded with a vent 50 for discharging uncondensed vapor or air, preferably outside the building housing the still. A priming line 51 is provided leading from the moisture filter 49 to the suction side of the pump to assist in sealing and priming the pump.

In the operation of a device embodying this invention the creation and maintenance of a proper vacuum results in a marked economy of steam and condensing water since the boiling temperature of the liquids usually distilled is lowered between and degrees Fahrenheit by distillation under a vacuum of'25 to 27 inches'of mercury. The vacuum pump is chosen of a size sufiicient to maintain such a vacuum under the'maximum output conditions and is supplemented for initial starting purposes by introducing a steam through the evacuating jet, the steam driving out the air and being itself condensed to help form the initialvacuum quickly. The use of the evacuating jet reduces the size of the vacuum pump required and also results in the establishment of proper 0perating conditions in a fraction of the time that would be required were a much larger pump depended upon to produce the initial vacuum. I

The normal degree of vacuum is suflicient to draw in the raw liquid, even from a distance or from an underground storage tank if such is used. This results in making the still entirely self-feeding, the feed regulator .being provided only to maintain a definite liquid level within the vaporizer. From the feed regulator or through the bypass if open, the raw liquid passes through the preheater, coil which is of relatively small pipe intended to, maintain a suflicient velocity of flow to prevent deposition of the foreign matter car- 'ried by the liquid. The preheater also has a condenser efi'ect on the vapor discharged from the vaporizer and thus results in a double gain in efliciency.-

The heating of the vaporizer is accomplished by a combination ofthe wet and dry methods, the calendria or steam drum furnishing a dry heat and the agitating jet mixing steam with the solvent which steam is condensed and gives up its latent heat of vaporization to the liquid until the vaporizer reaches its normal operating temperature, thus resulting in a rapid rise in temperature when starting from cold. In practice the combined use of the evacuator andagitating jets will permit starting up. a cold still in improved and simplified vacuum distillation prehe'ater coils in said vapor outlet casing and apparatus that can be rapidly brought into action and will be continuous and practically automatic in'operation.

I am aware that many changes may be means for controlling said feed supply to a constant fluid level in said vaporizer.

6; A vacuum distillationapparatus comprising a closed vaporizer, a steam injector made and numerous details of construction and dry steam heating means for heating the Lmay be varied through a wide range without departing from the principles of this invention, and I, therefore, do not purpose limiting the patent granted hereon otherwise than necessitated by the prior art.

I claim as my invention:

1. A vacuum distilling apparatus comprising a vaporizer, a condenser, a vapor outlet casing from the still connected with said condenser to partially support the same in any one of various selective positions about the vaporizer, a raw liquid preheater coil mounted in said vapor outlet,-a feed regulator for. supplying raw liquid to said preheater, heating means for said vaporizer comprising a steam calandria mounted therein, a steam supply line connected therewith, an evacuator jet also connected with said steam line for initially establishing a vacuum in said still, and an agitating jet also connected to said steam line and ositioned beneath said calandria for heating as well as agitating the contents of said still.

2. A vacuum vaporizer comprising a closed vessel in two sections having a bolted joint,

a steam calandria built intothe lower of said sections and having a large central passage surrounded by smaller tubes containing spiral deflection strips, and means for maintaining a liquid levelin said vaporizer partially submerging said calandria.

4. A vacuum vaporizer comprising a closed vessel in two sections having a bolted joint, a steam calandria built into the lower of said sections and having a large central passage, surrounded by smaller tubes containing spiral defiecting strips, means for maintainin a liquid level in said vaporizer partially submerging said calandria, and means for introducing fresh liquid into the central-passage of said calandria.

5. 'A vacuum distillation apparatus comprising a closed vaporizer, means for'heating the same, a condenser mountable in various positions upon the sides of the vaporizer, a'

vapor outlet casing connecting the vaporizer to the condenser, said casing being mountable, in various positions on the'va orizer to correspond with the chosen position of the condenser, a raw liquid feed supply including same, a condenser mountable in any of various positions upon the sides of the vaporizer, a vapor outlet casing connecting the vapor izer to the condenser, said casing being' mountable in various positionson the vaporizer to correspond with the position of the condenser, 'a raw liquid feed supply including preheater coils in said vapor outlet casing and means for controlling said feed supply to obtain a constant fluid level in said'vaporizer.

7. A vacuum distillation apparatus com- I prising a closed vaporizer, a steam calandria .for heating the same, a steam evacuator jet for initially creating a vacuum in said vaporizer, a condenser mountable in various positions upon the sides of the vaporizer, a vapor outlet casing connecting the vaporizer to the condenser, said casing being mountable in various positions on the vaporizer to correspond with the selected position of the condenser, a rawliquid feed supply including 'preheater coils in said vapor outlet casing and means for controlling said feed supply to maintain a constant fluid level in said vaporizer.

8. A vacuum distillati prising a closed still, means for heating the same, a steam evacuator. ct tor initially creating a vacuum in sai still, a condenser mountable in various positions uponthe side I of the still, a vapor outlet connecting the still to the condenser, said casing being mountable in various positions on the still to correspond with the closer position of the condenser, a raw liquid feed supply including preheater coils in said vapor outlet casing and means for controlling said feed supply to a constant fluid level in'said still,

on apparatus com- A 9. In a distilling apparatus a cylindrical vaporizer having a central outlet, a condenser mountable in various positions on the sides of saidvvaporizer, a vapor outlet casing connecting the central outlet of the vaporizer to the condenser and partially supporting the latter, a raw liquid feed supply including preheater coils in said vapor outlet casing and means for controlling said feed supply to maintain a constant fluid levelin said vaporizer i 10. In 'a distilling apparatus a cylindrical vaporizer, heating means for said vaporizer, a condenser mountable in various positions on the sides of said vaporizer, a vapor outlet casing connecting the central outlet of the vaporizer to the condenser and partially sup-- port-ing the latter, a raw liqui feed supply including preheater coils in said vapor outlet c'asingand means between the preheater and raw liquid supply for -controllingsaid feed supply to a constant fluid level in said vaporizer,

11. In a distilling apparatus a cylindrical 5 vaporizer, a steam evacuator jet for initially creating a vacuumin said vaporizer, a condenser mountable in various positions on the 1 sides of said vaporizer, a vapor outlet casing connecting the central outlet of the still to 10 .the condenser andpartiallysupporting the latter, a raw liquid feed supply including preheater coils in said vapor outlet casing and means exterior to the apparatus for controlling said feed supplyto a constant fluid 15 level in said-vaporizer.

12. In a distilling apparatus a cylindrical, vaporizer, heating means for said vaporizer, a steam evacuator jet for initially creating a vacuum in said vaporizer, a condenser mountan able in various positions on the sides of said. j

vaporizer, a vapor outlet casing connecting the central outlet of the vaporizer to the condenser and partially supporting the latter, a raw liquid feed supply including preheater g5- coils in said vapor outlet casin and means for controlling said feed supp y to obtain v a constant fluid level'in said-vaporizer.

13. A vacuum vaporizer com rising a closed vessel, a steam calandria t erein for so heating the same and comprising aseries of tubesarranged about a relatively large central passage, said tubes containing spiral deflecting strips, a feed regulator for a. raw liquid supply to the vaporizer a preheater 86 receiving the liquid from said regulator, and

a discharge pipe from said preheater extend-' inginto the central passage of said calandria. In testimony whereof I have hereunto subscribed my name at Chicago, CookxCounty,

40 Illinois. a

JOHN H. HILLS. 

